Safety apparatus for liquid fuel containers



Feb. 1, 1938. K H 2,106,750

SAFETY APPARATUS FOR LIQUID FUEL CONTAINERS Filed May 31, 1934 Patented Feb. 1, 1938 SAFETY APPARATUS FOR LIQUID CONTAINERS Nicholas E. Koch,

FUEL

Los Angeles, Calif.

Application May 31, 1934, Serial No. 728,459

13 Claims.

My invention relates, in one respect, to an apparatus assembly by which an inert gas may be contained in the upper part of a fuel tank in which the fuel or gases from the fuel are apt to 5 develop with air, an explosive mixture.

A use for my invention is in connection with fuel tanks used to supply internal combustion engines in which usually, as the liquid fuel is used from the tank, the upper portion of the tank becomes filled with air. This air with the vapors given off by the fuel, frequently forms an explosive mixture, which, if it explodes, will not only destroy the tank and ignite the vapor, but also probably ignite the fuel spread in the explosion. Usually such tanks have an air vent to allow inflow of air as the liquid fuel is drawn out of the tank.

An object and feature of my invention as regar-(ls the fuel tanks for supply of internal com- 00 bustion engines is in flowing part of the exhaust tank adjacent the top in order to prevent entry of air. This provides an inert gas in the top of the fuel tank. When using my invention, the filler opening should have an air-tight cap.

Another feature of my invention in order to prevent any flames from the exhaust gases from reaching the tank is the employment of screens preferably of fine mesh wire which will stop any 30 fiamesfrom reaching the contents of the tank. Another use of my invention is in preparing fuel tanks for welding operations, or the like. It has been found that even if the liquid fuel is apparently completely drawn out of the fuel tank 35 that it is still dangerous to attempt to weld a tank while there is air in such tank, as this air mixing with any residual vapors or vapors arising from fuel absorbed in the pores of the metal of the tank, sometimes causes explosions. There fore, a further use of my invention is in filling empty fuel tanks with an inert gas and passing this inert gas through the tank a suficient period of time to form a non-combustible mixture in the tank. I find a ready means to supply the inert gas is by using the explosion products of combustion of an internal combustion engine, forcing such exhaust gases in the tank through the filler opening and driving the waste gases through a discharge on another portion of the tank. In this case, I preferably use screens of a wire mesh fabric on the infeeding pipes and the pipe provided for the outflow. The screen on the outflow pipe is provided so that a test of the gas to determine if it has combustible matter is made by a torch, or the like, or a test flame gases of the engine into and through the fuel 7 at the tank discharge. When this test flame dies out or the torch flame is blown out by the noncombustible gases from the tank, the tank may be considered as safe for welding or similar operations in which a flame or an electric arc is applied to the tank.

My invention is illustrated in the accompanying drawing, in which:

Fig. 1 is a perspective drawing somewhat in diagram of the use of my invention in connection with a fuel tank for maintaining an incombustible gas in the tank.

Fig. 2 is a perspective drawing in diagram showing the application of my invention to an empty fuel tank to be welded or the like in which an inert gas is blown through the tank.

Fig. 3 is a longitudinal section on the line 3 -3 of Fig. 1 through the flame trap.

Fig. 4 is a longitudinal section through the bypass to the fuel tank of Fig. 1.

Referring first to the construction of Fig. 1, a

fuel tank is indicated by the numeral II. This may be of an ordinary type used in connection with supplying fuel for internal combustion engines and is illustrated as having a filler cap l2 which forms an air tight seal at the filler opening. The upper portion of the tank is provided with a pipe fitting I3, this being preferably at one end and in the top and adjacent the other end there is an outlet pipe fitting I4. The exhaust pipe from an internal combustion engine is indicated at l5 having an open exhaust end 16. To this pipe there is connected a by-pass pipe ll, the connection being by means of a T type of fitting l8. Inthis T fitting a by-pass valve I9 is used. This valve has a seat 20 and a valve flap 2| pivoted at 22 and having an operating handle 23 for turning the flap to a desired position to secure the amount of by-pass products of combustion required.

In order to prevent a flame from the exhaust of an internal combustion engine reaching the tank I utilize a flame trap designated by the assembly numeral 24. This trap is connected in the by-pass pipe i1 and comprises a shell 25 held between a pair of collars 26, these collars being secured to the pipe 11, and in this shell there is a holder tube 21 with a plurality of transverse screens 28. These screens are preferably-made of a wire mesh fabric. In order to cool the flame trap a series of fins 29 are secured to the outside of a shell. The exhaust gases, after passing through the tank, are discharged through the exv haust pipe l4 connected to the pipe fitting I 4.

In the operation of my invention to supply a I Ol fuel tank or a tank which has had'a combusti-' portion of the fuel tank instead of allowing air to flll in this tank as.-the fuel is exhausted, a small amount only of the exhaust gases need be passed through the tank and the connection should be through the upper portion of the tank above the fuel level. a

Ordinarily, a liquid fuel tank is provided with a small air inlet opening, usually in the closure cap, to allow entry of air, as the liquid fuel is used, but this air with the vapors from the oil fuel are apt to form an explosive mixture. This .is prevented by my invention. The by-pass flap valve 2| may be regulated so that the desired portion of the exhaust from the internal combustion engine exhausting through the pipe l5'may be forced into the top of the tank through the fitting l3 and the surplus inert gas over that necessary to take the place of the fuel used by the engine is exhausted through the pipe fitting l4 and outlet pipe M, j

The flame trap 24, as shown in detail in Fig. 3, prevents any flame which may be blown through the'pipe l5 and by-pass pipe I1 entering the fuel tank; and in order to .maintain the screens cool, and also to cool the exhaust' gases entering the tank I employ the cooling fins 29 or an equivalent cooling mechanism.

, In Fig. 2 I illustrate my invention as applied to filling a tank designated by the numeral 30 which is to have a welding or other job performed thereon. As above mentioned, it is sometimes difficult even after emptying a liquid ble fuel to thoroughly exhaust the explosive gas or vapors in the tank and, therefore, it is dangerous to weld such tanks until there is assurance that there is no explosive mixture in the tank. I found that a simple manner of filling the tank withan inert gas is to use a filling pipe 3| which receives the exhaust of an internal combustion engine. This pipe has a discharge end 32 which is inserted through the filling opening 33 of the tank after removal of the clo- 45 sure cap. The same flame arresteror flame trap 24 is used as in connection with Fig. 1 although in this case, as it is immaterial whether or not the gas is hot, the cooling flns would be omitted. At the exhaust end I also preferably use a flame arrester 34 which may be of the same construction as the flame trap 24 but the cooling fins may be omitted.

In the operation of the construction of Fig. 2, after the' fuel tank is emptied of all fuel the exhaust gases from an internal combustion engine are blown through the tank for a period of time until it is judged that the air and any explosive gas or vapors in the tank have been exhausted. A test may be made by initially ignitingthe air and vapors blown from the flame trap 34 at its outlet end 35 and this gas and flame will burn as long as a combustible mixture is being forced out of the tank but when the exhaust gases commence to flow through the pipe l4 and the flame arrester 34 'the flame is extinguished.

The object of the flame trap on the outlet is to prevent the test flame from working into the tank and causing an explosion.

Another way of testing to flnd if the tank has an inert mixture therein is by connecting a hose on the outlet 35 and-taking this to the air inlet of the carburetor of a gasoline or equivalent engine. While air is being drawn from the tank the engine will keep going but when the inert used gases enter the air intake of the carnoncombustible, that is, an inert gas, in the upper buretor the engine will cease operation, thus showing that the tank isfilled with an inert gas.

A test of the gas discharged at 35 may also be made by means of a torch which, when held close to the waste gas outlet, will be blown out when the inert gases blow through the tank, and when the tank is properly filled with inert gases it is safe to perform a welding operation on the tank.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined in the appended claims. l

I claim:

1. In a device as described, a fuel tank having a filler opening with a closure means therefor, an inlet pipe connected to an upper portion of the tank, said tank having an outlet adjacent an upper portion and remote from the inlet pipe, an exhaust pipe adapted for connection to an internal combustion engine and having a discharge opening, the inlet pipe being connected to the exhaust pipe, and a by-pass valve to by-pass a portion of the exhaust gases from the exhaust pipe through the inlet pipe to the tank.

.2. In a device as claimed in claim 1, a closure plug for. the tank forming a closure after removal of the inlet pipe, a pipe insertable through the filler opening of the tank, said pipe being connected to the exhaust of an internal corn,- bustion engine.

3. In the method of rendering a fuel tank n explosive, comprising exhausting the major portion of the exhaust gases of an internal com bustion engine'to atmosphere and by-passing a minor portion of said gases through the upper part of a fuel tank to' atmosphere to thereby exhaust the explosive gases in the tank or to dilute such gases a sufficient amount to prevent an explosion.

4. In the method as claimed in claim 3, cooling the by-pass exhaust gases prior to flowing such gases into the tank.

5. In the method of rendering a fuel tank nonexplosive, comprising emptying the fuel tank of fuel, then flowing an inert non-explosive gas noncondensable at ordinary temperatures and pressures into one portion of the tank and out of a remote portion to thereby fill the tank with a non-explosive gas.

6. In the method of preparing fuel'tanks for welding, a preliminary step of rendering such fuel tank non-explosive, comprising, emptying the fuel tank of fuel then flowing an inert non-explosive gas which is non-condensable at ordinary temperaturesand pressures into one portion of the tank and out of a remote portion thereof, and continuing flowing such inertgas until all of the combustible vapors have either been 'removed from the tank or so diluted as to render the mixture in the tank non-explosive.

7. In the method of preparing liquid fuel tanks render the same non-explosive.

8. In a device as described, a fuel tank having an outlet for vapors located above the high level of fuel in the tank when the tank has its maximum 73 supply of fuel, said outlet having a flame extinguisher incorporated therein, means to discharge the exhaust gases of an internal combustion engine in one portion of the tank and circulate such gases and discharging the exhaust gases with residual vapors or fuel through the outlet and thereby through the flame extinguisher.

9. In a device as described, a fuel tank having a filler opening with a closure cap, an opening in the tank having an exhaust pipe from an internal combustion engine fitted therein, an outlet from the tank located above the normal high level of fuel, whereby exhaust gases may be circulated through the tank above the level of the fuel therein and such exhaust gases with vapors from the fuel discharged through the said outlet.

10. In a device as claimed in claim 9, the exhaust pipe from the internal combustion engine having a flame arrester therein and cooling fins on the outside of the pipe to arrest anyflame in the exhaust gases and to cool such gases prior to entrance into the tank.

11. In a device as claimed in claim 9, a sealing B5 plug attached to the tank opening in place of the exhaust pipe, the filler cap being removed and the exhaust pipe from the engine inserted therein, the outlet from the tank having a flame extinguisher whereby exhaust gases may be circulated through the tankand carry the residual fuel vapors through the outlet and the flame extinguisher at the outlet.

12. In a device as described, a liquid fuel tank having a gas outlet with a flame extinguisher thereon, and means to flow the exhaust gases from an internal combustion engine into another portion of the tank to circulate such gases through the tank and discharge at the said outlet.

13. In the method of preparing liquid fuel tanks for welding as claimed in claim 7, cooling the products of combustion gases prior to their entering into the tank to increase their density thereby causing the entering gases to flow to the bottom of the tank and displace Vapors of the liquid fuel in the tank upwardly, the vapors from the tank and the products of combustion being exhausted from an upper portion of the tank.

NICHOLAS E. KOCH. 

